Method of making wood-base cutting dies



I. F. MURPHY.

METHOD OF MAKING WOOD BASE CUTTING DIES. APPLICATION FILED SEPT. 29,1920.

Patented Jan. 3, 1922."

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T (AZ? wit-om it may concern METHOD osiirezine Ween-BASE.ooirrme'miis,

Specification of Letter s P atent.

. Patented Janet 19 22.

Application filed September 29,;920. serm No. "413,642.

Be itknown that 1, JOHN F. Monr'rrir, a

Vorcester, in the county of "Worcester and Commonwealth ofMassachusetts, have 1nvented anew and useful Improvement in a Method ofMaking Wood-Base Cutting'D'ies, .of' wliich theyfollowing, together withthe accompanying drawings, is a specification. 10

The present invention relates to the manu facture of dies,and inparticular to an im-' proved type of'wood 'base die, whereinit ispossible to obtain a maximum of accuracy in fitting the cutting bladestothe wood base 'or backing, and at the same time permitof said bladesbeing suitably hardened and tempered.

The invention, lnVOlVlIlg various new departures in the manufacture ofwood base dies, is fully set forthin the following de scription,reference being had to the accompanying drawings, whcrein- Fig. 1 is aplan view showing the preliminary formation of the design for the die"in a block of relatively soft wood.

Fig. 2 is a perspective view showing the die blades temporarilyin placein said blockl Fig. 8 is a plan view showing the imprint of said dieblades on permanent block of hard wood which is to form the base of thedie. I

Fig. 4 is a perspective view showing the manner of removing the dieblades from the temporary support, and

Fig. 5 is a sectional view showing the manner of inserting the tempereddie blades in the permanent base of backing.

Like reference characters refer to like parts in the different figures.

The manufacture of a wood base die as at present practiced, involves,generally speaking, thesawing of the desired outline or pattern in asuitably prepared block of wood; the die pieces, having been shaped orbent t conform as nearly as possible to the outline as cut by the saw,are inserted and worked into the lrerf.

The results of this process are in the main unsatisfactory; it ispractically impossible, owing to variations between the blade pieces andthe saw kerf, to obtain a firm enough setting of the blades which willenable the die to stand up under continued and prolonged hard usage;moreover, when the pattern or outline involves sharp reentrant turns orangles, the metal of the blade, as in v "sorted 'inthe saw kerf, must besoft enough citizen of the United States, residing at" to permit ofbeing for'ced andbentint'o-such angles, and, consequently, is precludedfrom having the proper hardnessxand temper 1n the completed die.

The above and other defects andfshortcomings in the manufacture "of woodbase dies are overcomeinthe proces'sfof manufacture contemplated byinvention, in the following manner :The outline of the pattern'is firstlaid' off on a non-permanent block of wood, preferably of arelativelysoft laminated piece, and this outline is sawed,as shown inFig. 1 ,"so as to provide a continuous kerf or slot 1 between the body 2er the block andthe inner portion 3. The die blade material, inrelatively'soft untempered form, and in a plurality of pieces, asindicated'in Fig. 2, is worked and bent into such; shape 2 and 3, in themanner well known in the art.

dinary'u'se, as above described. The mode of manufacture of my improveddie, starting from this point, is as follows The assembly of Fig. 2 isused for the purpose of making a true imprint of the die blade on a hardblock of wood 4, which is preferably of the usual laminated formation.This impression or outline is the actual outline of the completed die,and it differs in most cases from the original outline 1 of Fi g. 1,for'the reason that it is never possible to make the metal conformabsolutely to said original outline. Hence this second outline on thepermanent hard block 4, is one which, when sawed, will conformabsolutely to the bent metal, as distinguished fromthe approximateconformation between saw kerf l and the bent metal. In other words, thesaw kerf 5 in the permanent block L is cut to the exact form andconfiguration of the formed die blades, whereby an exact and accuratefit is assured; on the other hand, no such fit can be obtained in theassembly shown in Fig. 2, since the metal can never be bent and shapedaccurately enough to fill all fthe interstices and crevices of the sawher 1.

I asto conform to the Out ine, being inserted. and held'in thekerf 1between the portions The next step in my improved method is permanentblock; this is done by cutting sand-breaking away the outer and innerporno longer necessary to retain the material f inch narrower than'theblades, so that said exertion of considerable pressure.

complish this resultand, at the same time,

in ductile form'; the slot or kerf 5 into which it is to be inserted,has been given the precise form required. After hardening and tempering,the blade pieces are entered, cutting edge first, into the kerf 5, thelatter preferably being a few thousandths of an blades must be forcedinto the kerf by the guard against the collapse of the inner basep'ortion 6, the blade pieces are forced through the kerf in a suitablepress, as in-'. .dicated in Fig. 5, so arranged that the cut-J tingedges, as they project downwardly through thekerf, come into contactwith a yielding surface,'preferably provided by a block 7, set inopposition to the permanent block a and having its grain runninglengthwise at right angles and perpendicular to ,.-the grain of theblock 4.

By'this process the blade pieces are driven through, compressed and heldin a kerf 1 which corresponds exactly to their outline,

the cutting edges imbedding themselves in a surface which is maintainedat all times in close contact with the surface of portion 6,

,thuspreventing breakage and collapse of the latter. After the dieblades have thus To ac- 1. The herein described method of making a'woodbase die, which consists in forming and fitting the die blades to atemporary kerf or slot of the desired design, and thereafter insertingsaid blades in a kerf or slot which is cut to conform to the actualoutline produced by said blades, as shaped to and held in said firstmentioned kerf; I

2. The herein described method of making a wood base die, which consistsin reproducing the actual outline of the formed die blades as held in atemporary support upon a permanent die base, tempering said blades afterremoval from said temporary support, and inserting them in a kerf orslot that conforms to the outline reproduced in said permanent base.

3. The herein described method of making a Wood base die, which consistsin forming and workingthe die blades as closely as possible to a slot orkerfyof the desired design, taking the imprint of said blades, as

.held temporarily in said slot or kerf, upon a permanent wood base,formlng'a slot or kerf upon said imprint, supporting said permanent baseagainst the grain end of a block, and forcing said blades through saidslot or kerf, to imbed themselves in the end of said block. .r

Dated this 27th day of September, 1920. JOHN F. MURPHY.

